This invention relates to a deployable barrier for confining floating pollutants, such as oil.
Barriers are known which comprise a series of buoyant boom sections interconnected by a cable, or the like, passing longitudinally therethrough and provided with a depending flexible skirt.
One of the difficulties encountered with the above mentioned construction is the prevention of leakage at the joints between sections, particularly in flowing water or when being towed. To allow free pivoting of the boom sections relative to one another, some clearance between sections is required. Furthermore, when boom sections are not individually attached to the cable, the clearances will not always remain evenly distributed, but rather tend to accumulate between some of the sections to form large gaps, particularly under the force of moving water. Because of the variations in gap size between boom sections, it is very difficult to prevent the leakage of pollutants, not only because of the gap itself but also because of the difficulties in maintaining sealed attachment between the skirt and boom in the region of the variably spaced joints.
Prior proposals to prevent separation and/or leakage at the joints involve adding substantial complexity and cost to boom construction.
Another difficulty with conventional barriers is that, as the relative velocity of the barrier to water is increased, due to towing and/or flowing water, there is a point, known as the first-loss speed, at which water passing under the skirt entrains oil causing it to pass under the barrier.